2012 Annual Report
1.B. Identify new grazing management and supplementation strategies that complement grazing preferences of dairy cattle to optimize the utilization of mixed-species cool-season pastures of the Northeast U.S. and to reduce inputs costs for pasture-based producers.
2.A. Identify management systems that minimize net greenhouse emissions in forage, grassland, and energy crop systems in humid-temperate climates.
2.B. Determine optimal management and environmental benefits of perennial and annual bioenergy cropping systems in the Northeast U.S. to reduce production costs and increase yields.
1.B. Observational research will be conducted on pasture-based dairy farms feeding a range of supplementation strategies with varying pasture composition to characterize the effects of supplementation on grazing behavior and diet selection. Ingestive behavior will be quantified on during spring, summer, and fall grazing. Detailed feeding and milk production information will be collected from farm records and personal interviews. Continuous culture fermenters will be used to identify ruminal fermentation products that influence grazing patterns via post-ingestive feedback mechanisms. Sward-box studies will be used to evaluate cattle grazing behavior responses to monocultures and mixtures of selected grasses and legumes.
2A. Multi-location field plot and farm-scale trials will be conducted to determine the greenhouse gas emissions and economics of perennial and annual crops grown for bioenergy. Differences in C isotope discrimination (d13C) of C3 and C4 species will be exploited to partition respiration between new C respired from C3 plants such as orchardgrass and white clover and old C respired from the active pool of soil organic matter that has formed under the C4 species, big bluestem.
2B. Biomass yield, feedstock quality, and greenhouse gas emissions of current annual and proposed perennial bioenergy crops under the same climate and soil will be measured, and the resulting data will be used to validate the DAYCENT biogeochemical model at a site in the northeastern U.S.
1)was a cheaper fuel than fuel oil (could save consumers in NE US $2.3 – $3.9 billion annually),.
2)displaces more than twice as much petroleum when replacing fuel oil compared with gasoline, and.
3)is a cheaper GHG mitigation strategy when it replaces fuel oil rather than electricity in the NE US (reduces GHGs at a cost savings of $10 – 11.6 billion annually). This study highlights the importance of explicitly targeting GHG reductions and petroleum offsets so biomass is not distributed towards more expensive options, such as the electricity sectors as with RPS legislations. 3. Switchgrass establishment date and weed control method affect yield. Controlling weeds is important for accelerating biomass production from switchgrass, however, since it is a new bioenergy crop, few chemical weed management options are available. ARS researchers at University Park, Pennsylvania tested both approved and new chemicals and establishment time as methods to control weeds. Agricultural Research Service (ARS) and Penn State University scientists found that when a combination of new and approved chemicals were used to control weeds, the earlier seeding date yielded more biomass. However, with a later seeding date, when weed pressure was lower, all treatment methods were equally effective. This study highlights the importance of identifying new weed management strategies to maximize the yields of switchgrass. 4. GHG mitigation strategies for bioenergy feedstock production. State and federal regulations reward innovation for improvements in the life cycle greenhouse gas (GHG) emissions of the fuel pathway and the type of feedstock chosen for conversion to biofuel. However, there is not an incentive strategy in place to reward the further reduction of GHG emissions from production of a particular feedstock. Agricultural Research Service (ARS), National Renewable Energy Laboratory, Drexel University, and DuPont scientists reviewed and analyzed data from GHG life cycle assessments, demonstrating that feedstock production can contribute more than 50% of the total GHG emissions. Instead of tracking all the components of life cycle GHG emissions in feedstock production, which would be overwhelming, ARS researchers at University Park, Pennsylvania identified the most important components contributing to GHG emissions which have potential for mitigation, N fertilizer material, N2O emissions, and tillage impact on soil carbon. This study provides a practical path forward to capture further reductions in life cycle GHG emissions by adopting the identified mitigation strategies.
Wilson, T., Mcneal, F.M., Spatari, S., Abler, D.G., Adler, P.R. 2011. Densified biomass can cost-effectively mitigate greenhouse gas emissions and address energy security in thermal applications. Environmental Science and Technology. 46(2):1270-1277.
Curran, W.S., Ryan, M.R., Myers, M.W., Adler, P.R. 2011. Effectiveness of sulfosulfuron and quinclorac for weed control during switchgrass establishment. Weed Technology. 25:598-603.
Skinner, R.H., Wagner-Riddle, C. 2012. Micrometeorological methods for assessing greenhouse gas flux. In: Liebig, M.A., Franzluebbers, A.J., Follett, R.F., editors. Managing Agricultural Greenhouse Gases: Coordinated Agricultural Research through GRACEnet to Address our Changing Climate. San Diego, CA: Elsevier. p. 367-384.
Skinner, R.H., Zegada-Lizarazu, W., Schmidt, J.P. 2012. Environmental impacts of switchgrass management for bioenergy production. In: Monti, A. editor. Switchgrass: a valuable biomass crop for energy. London, United Kingdom: Springer-Verlag. p. 129-152.
Skinner, R.H. 2011. Quantifying rhizosphere respiration for two cool-season perennial forages. Crop Science. DOI: 10.2135/cropsci2011.03.0155.
Morgan, J.A., Skinner, R.H., Hanson, J.D. 2001. Nitrogen and CO2 affect regrowth and biomass partitioning differently in forages of three functional groups. Crop Science 41(1):78-86.
Comas, L.H., Goslee, S.C., Skinner, R.H., Sanderson, M.A. 2011. Quantifying species trait-function relationships for ecosystem management. Applied Vegetation Science. 14(4):583-595. DOI: 10.1111/j.1654-109x.2011.01136.x.
Adler, P.R., Del Grosso, S.J., Inman, D., Jenkins, R.E., Spatari, S., Zhang, Y. 2012. Mitigation opportunities for life cycle greenhouse gas emissions during feedstock production across heterogeneous landscapes. In: Liebig, M., Franzluebbers, A.J., Follet, R.F., editors. Managing Agricultural Greenhouse Gasses: Coordinated agricultural research through GRACEnet to address our changing climate. New York, NY: Elsevier Inc. p. 203-219. DOI: 10.1016/B978-0-12-386897-8.00012-7.
Adler, P.R. 2005. Effect of a temporal carbon gradient on nitrogen and phosphorus dynamics and decomposition during mesophilic composting. Communications in Soil Science and Plant Analysis. 36:2047-2058.
Curran, W.S., Ryan, M.R., Myers, M.W., Adler, P.R. 2012. Effects of seeding date and weed control on switchgrass establishment. Weed Technology. 26:248-255. DOI: http://dx.doi.org/10.1614/WT-D-11-00078.1.
Davis, S., Parton, W., Del Grosso, S.J., Keough, C., Marx, E., Adler, P.R., Delucia, E. 2011. Impact of second-generation biofuel agriculture on greenhouse gas emissions in the corn-growing regions of the US. Frontiers in Ecology and the Environment. 10:69-74.
Sanderson, M.A., Goslee, S.C., Franzluebbers, A.J., Kiniry, J.R., Owens, L.B., Spaeth, K., Steiner, J.L., Veith, T.L. 2011. Pastureland Conservation Effects Assessment Project: Status and expected outcomes. Journal of Soil and Water Conservation. 66(5):148A-153A.
Soder, K.J., Hoffman, K., Chase, L.E., Rubano, M.D. 2012. Case study: molasses as the primary energy supplement on an organic grazing dairy farm. Professional Animal Scientist. 28:234-243.
Soder, K.J., Brito, A.F., Rubano, M.D., Dell, C.J. 2012. Effect of incremental flaxseed supplementation of an herbage diet on methane output and ruminal fermentation in continuous culture. Journal of Dairy Science. 95(7):3961-3969. DOI: 10.3168/jds.2011-4981.
Del Grosso, S.J., Parton, W., Adler, P.R., Davis, S., Keogh, C., Marx, E. 2012. DayCent model simulations for estimating soil carbon dynamics and greenhouse gas fluxes from agricultural production systems. Book Chapter. New York, NY: Elsevier Inc. p. 241-250.